Terminal strap,contact jaw member,and connector assembly for electrical switch

ABSTRACT

THE TERMINAL STRAP INCLUDES A REAR PLATFORM NORMALLY MOUNTED ADJACENT A REAR WALL OF AN ENCLOSURE FOR THE SWITCH, A FRONT PLATFORM, AND A CONNECTING PORTION JOINING THE FRONT AND REAR PLATFORMS. A STATIONARY CONTACT JAW MEMBER IS SECURED TO THE REAR PLATFORM. A PAIR OF CONNECTORS, EACH INCLUDING A CONNECTOR BODY HAVING A CLAMPING SCREW   THREADEDLY MOUNTED THEREIN, ARE SECURED TO THE FRONT PLATFORM RESPECTIVELY BY A PAIR OF CAPTIVE BOLTS HAVING HEAD PORTIONS DISPOSED REARWARDLY OF THE FRONT PLATFORM RESPECTIVELY ON OPPOSITE SIDES OF THE CONNECTING PORTION IN NONROTATABLE RELATIONSHIP THEREWITH.

1 l u t t rte to [72] lnventor Bari-i511. Stnnbaclr Lexington, Ky.

[21] Appl. No. 023,259

[22] Filed May 9, 1969 [45] Patented .flnne 20, 1071 [73] Assignee Squnre B. Company lPnrlr Ridge, 111.

[54] TEBMTNAIL STBAIP, CONTACT JAW MEMBEB,

ANT) CQNNECTOB ASSEMBLY 1E0 ELECTBTCAIL BWHTCB 0 Clnimn, 6 Drawing Eign.

[52] 11.8.1131 200/166, 339/258,200/170 [51] llnLCfl 1-101h 1/00 [50] Eield 0T Search 200/166 (E), 170, 166(1CTS), l62;317/1l2, 118; 337/9, 191, 192, 193; 339/32 (M),258 (F), 259 (F), 262

[56] Belierencm Cited UNlTED STATES PATENTS 2,845,512 7/1958 Burt etal. 200/162 3,027,440 3/1962 Daly 200/166(E) 3,075,164 1/1963 Humpage et al.,..i200l166(lCTS)(UX) 3,265,830 8/1966 Kobryner .l200/l66(E)(X) 3,423,723 1/1969 [(obryner 339/259(F) FOREIGN PATENTS 172,943 10/1960 Sweden 339/258(]F) 885,319 12/1961 Great Britain 339/258(F) Primary Examiner-H. 0. Jones Attorneys-Harold J. Rathbun and Paul J, Rose ABSTRACT: The terminal strap includes a rear platform normally mounted adjacent a rear Wall of an enclosure for the switch, a front platform, and a connecting portion joining the front and rear platforms. A stationary contact jaw member is secured to the rear platform. A pair of connectors, each including a connector body having a clamping screw threadedly mounted therein, are secured to the front platform respectively by a pair of captive bolts having head portions disposed rearwardly of the front platform respectively on opposite sides of the connecting portion in nonrotatable relationship therewith.

Pmmmmam 358M413 SHEET 1 BF 2 FIG. I +4 INVENTOR.

HARRIS I. STA/VBAQK BY PATENTEU M28197! SHEET 2 BF 2 .INVENTOR. HARRIS I. S774/VBAC/f TERMINAL STRAP, CONTACT .IAW MEMBER, AND

CONNECTOR ASSEMBLY iiOlit ELECTRICAL SWITCH This invention relates generally to a terminal strap, stationary contactjaw member, and connector assembly for electrical switches, and more particularly to an assembly in which the terminal strap provides a pair of front and rear mounting surfaces respectively in spaced parallel planes, the stationary contact jaw member being secured to the rear mounting surface, and a pair of connectors being secured to the front mounting surface respectively by a pair of captive bolts held against rotation by engagement of their respective head portions with the terminal strap.

In the drawings, FIG. I is a front elevational view of one pole portion of a multipole fusible safety switch including a terminal strap, stationary contact jaw member, and connector assembly constructed in accordance with this invention;

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 11; FIG. 3 is a sectional view taken along the line 33 of FIG.

FIG. 41 is a fragmentary sectional view taken generally along the line d l ofFIG. I;

FIG. 5 is a fragmentary sectional view of the structure of FIG. it taken along the line 5-5 of FIG. 4; and

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 3.

The drawings illustrate a single pole portion of a multipole fusible safety switch similar to that disclosed in U.S. Pat. No. 3,339,047, issued Aug. 29, 1967. A base Ill molded ofinsulat ing material is securable to the rear wall of an enclosure (not shown). Secured to the base It] by a pair of screws 12, only one of which is shown in FIG. 4, is a terminal strap I4 which includes a rear platform 14a and a front platform Mb joined by a connecting portion Me (FIG. 3).

A relatively large connector including a stepped body 16 (FIGS. I and 3) having a pair of clamping screws I8 threadedly mounted therein is secured to the front platform Mb by a bolt 19 and a nut 20. Further, a relatively small connector including a stepped body 22 having a clamping screw 24 threadedly mounted therein is secured to the platform Mb by a bolt 25 and a nut 26. The two connectors are provided because a single wire cable large enough to carry the current for which the switch is designed would be too stiff and unwieldy. The bolts 19 and 25 are held captive in the platform Mb by a pin 28 disposed in the connecting portion l tc, the heads of the bolts being disposed between the pin 28 and the platform I tlb. Further, the bolts I9 and 25 are disposed on opposite sides of the connecting portion Ida and a flat surface on the head of each bolt abuts an adjacent surface of the connecting portion Isle to prevent rotation of the bolts.

A stationary contact assembly including a double jaw member 30 (FIGS. 3 and 4i) and a contact pressure spring member 32 is secured to the rear platform Mu by a bolt 33 and a nut 34, the head of the bolt 33 being recessed within the base II. A hoodlilte casing 36 molded of insulating material is secured on one side to the rear platform 14a by a screw 37 (FIG. El) and on the other side to the base III] by a pair of screws 38 (FIGS. I and 3).

Secured within the casing as are a pair of complementary support members it) and ill formed of cold-mold, arc-suppressive insulating material such as melamine bonded oxides or hydrates of aluminum or magnesium. A pair of screws 42 and 43 are cooperating nuts M and d5 secure the support members 40 and 41 respectively to opposite sidewalls of the casing 36. In addition, the casing 36 is provided with a pair of projections 36a and 36!: (FIGS. 5 and b) which extend into appropriate recesses respectively in the support members All] and ll. Adjacent the front end, the upper wall ofthe casing 36 is provided with a series of vent holes 36c. A plurality of generally U-shaped metal plates 68 are mounted in spaced relationship in complementary grooves provided in the support members till and d1.

Also secured to the base Ill by a pair of screws 5t) (FIG. 4) is a combination fuse and switch blade mounting means in cluding a pair of aligned generally U-shaped spring members 52 (FIGS. I and 2), a generally lJ-shaped mounting member 56 disposed within the spring members 52, a generally L- shaped mounting member 56 disposed within the mounting member 5d, and an anchoring plate fi'iil into which the screws 50 are threaded to secure the members 52, 543, and 56 to the base It). A pin 60 is mounted adjacent one end in the member 56 and adjacent the other end in one leg portion of the member 54. A switch blade 62, movable by blade actuating means not shown, is pivotally mounted on the pin bill. The end portion of the pin till mounted in the one leg portion of the member 54 is larger in diameter than the remainder thereof and is trapped between the switch blade s2 and one leg portion of one of the spring members 52 to prevent axial movement of the pin. A spacer M is mounted between the member 56 and the one leg portion of the member Ed adjacent the other end of these members from the pin tit). The spacer Ml may have a smaller diameter portion (not shown) projecting into either the member 56 or the member 54. Before being secured to the base It by the screws St), the assembly including the members 52, member 54, member iiti, anchoring plate 58, pin 60, switch blade 62, and spacer be is secured together by a pair of screws 66 also threaded into the anchoring plate fill.

Another base till (FIG. ll) molded of insulating material is securable to the rear wall of the enclosure (not shown) in spaced relationship to the base It). Secured to the base till is a terminal strap 70 similar to the terminal strap Ml and having connector bodies identical to bodies lb and 22 secured to the front platform thereof. A fuse clip 72 reinforced by a spring member 74 is secured to the rear platform of the terminal strap 70. A fuse 76 having blade terminals adjacent opposite ends is shown with one blade terminal mounted in the fuse clip 72 and the other blade terminal mounted between the member 56 and the other leg portion ofthe member 54.

As shown in FIGS. 3 and i, the support members 4% and M respectively include portions ltla and 41a disposed above the jaw member 36 and extending rearwardly of the front end thereof, where any are would originate upon separation ofthe switch blade 62 from the jaw member 30.

Further, as shown in FIGS. and 6, the support members respectively include portions dtlb and ill) which together substantially completely cover the plate db nearest the jaw member 3t) on the side of the plate facing the jaw member. in addition, as shown in FIGS. 4 and 5, the support members respectively include portions dtlc and 40.0 which support the plates 48 in spaced relationship and respectively line opposite walls of the casing 36. The construction and arrangement result in an arc suppressor which can repeatedly withstand interruption of larger currents than formerly possible with an arc suppressor of similar size.

The terminal straps M and 7b are shaped to dispose the connectors a considerable distance away from the rear of a switch enclosure, in order that a minimum of bending is required in relatively stiff multistrand power cables securable in the connectors.

I claim: 1

I. In a electrical switch, an assembly comprising an insulating base member, an electrically conductive terminal strap member including a rear platform portion secured to the base member, a front platform portion, and a connecting portion joining the front platform portion to the rear platform portion and spacing the front platform portion forwardly of the rear platform portion in a direction away from the base member, the platform portions being disposed in parallel relationship to each other and the rear platform portion extending farther from the connecting portion in one direction than the front platform portion extends, a stationary contact jaw member separate from the terminal strap member and secured to the rear platform portion, and a connector separate from the terminal strap member and secured to the front platform portion, the connector including a body having an aperture therein for receiving an electrical conductor and a clamping screw threadedly mounted in the body and suitable for securing an end portion of an electrical conductor in the aperture.

on opposite sides of the connecting portion of the terminal strap member.

3. in an electrical switch, an assembly as claimed in claim 2 wherein the bolts are captive on the front platform portion of the terminal strap member and each includes a head portion closely adjacent the connecting portion of the terminal strap member and held against rotation by engagement therewith.

4. In an electrical switch, an assembly as claimed in claim 1 including a switch blade and means mounting the switch blade for pivotal movement with respect to the base member and electrical engagement with and disengagement from the stationary contact jaw member, and wherein the connecting porti'on and the front platform portion of the terminal strap member and the connector secured to the front platform portion are spaced laterally of the switch blade. 

